I need some tuning help on a OS VSPEC
 

I have a new limited edition os vspec that I have about 2 qrts on now and I am fighting a high rev before it idles down. The top end runs great but when you let off the throttle it takes about 7-10 seconds before it will idle down. I have tried everything to adjust it and nothing will work. Someone told me the carb could be defective but I wanted to get some input before I have to buy a new carb. The fuel tank is new, clutch and bearings are new, air filter was clean, and fuel lines are new. I also made sure the linkage was adjusted properly as well.

The most common thing to look at is your linkage setup bro. Also, make sure you're not binding the slide with your return spring. Eliminate mechanical issues before getting into the engine.

Engine: there are people that are much more qualified than I am, so grain of salt stuff here. I'd look at the idle gap first and then seal it up to eliminate possible air leaks before digging deeper.

Linkage or servo check. Also check your trim on the radio and maybe recenter your throttle servo.

This will eliminate that from the equation. Then you can try to adjust the engine.

The linkage is bind free and the idle gap is good. I took the motor apart and sealed it with lucky7 prior to breaking it in.

Come out on your low end and turn up the idle if you need to. Make sure your mid needle is flush and at 1:00. Every 1/8th of a turn on that mid needle can open or close it up. To see what Im talking about you could take your HSN off the carb and look down into the mid needle and turn it. Just make sure that hole is open, flush with the outside of the carb body and at 1:00. You can always do a pinch test on the fuel line about 3 inches off the fuel nipple. You should get 3-4 seconds before it revs up and dies out. If it dies out before 3-4 seconds, it's too lean. If it dies out after 3-4 seconds it's too rich. This method is just a starting point/reference.

Fatten the bottom 1-2 hrs. Pinch test. Time it takes to spool up indicates rich or lean and how much it spools up indicates your idle gap setting. If nothing changes I'd pull the needles and replace the o-rings. Definitely sounds like the carb if it was a fairly sudden change. Look at the front bearing too. If you break-in super rich it creates crazy crankcase pressure and it's really easy to force a premature air leak.

Iono...my .02 cents.

Thanks for the replies. I will definently check some more stuff out tomorrow.

Make sure there are no air leaks. And then fatten the bottom a little bit but before you do that do the pinch test and count 1 onethosand 2 onethousand Etc and see how many you count to. Should be somewhere around 4

Posted this in the OS thread as well...

Air leak!:nod: A common source for air leaks on the v-specs is at the carb pinch bolt. With the v-spec one not being o-ring sealed, there's really nothing sealing it. Anytime I've seen those symptoms on a v-spec it has been from an air leak.;)

he said prior to brak in he sealed it with lucky 7 sealent. It sounds like to me is you got in a rush on break in then went for a track tune and now its all out of wack. I would say go back to stock tune settings and start all over also what breakin procedure did u do and how many tanks of break in? NEVER RUSH BREAK IN THE MOTOR WILL NEVER RUN GOOD!

your low speed needle is too rich,maks sure your idle gap is .5-.7mm:batman:

First i want to thank you for using Lucky 7 products. second i want to tell you that if you read the instructions L7 engine sealant is intended for external use only, no dis-assembly is required. Lucky 7 sealant is a coating, not a gasket. ;)

now for your tuning. getting the perfect mixture between the LSN, MRN, and idle will eliminate any 2 stage idle on any engine. first set your idle to 1-1/4 turns in from closed, and know you dont need to touch it more then 1/8 to achieve the perfect tune. then start leaning the lsn 1 hour at a time and you should notice the 2 stage idle becoming shorter and shorter as you lean the lsn. the 2 stage idle is simply the engine loading up and burning the excess fuel in the case, now with that said if you lean the lsn too much the idle will go high and stay high, turn it back out 1 hour till its stable. < now you're close. from here make fine tuning adjustment between the LSN, MRN and idle. understanding how the needles effect each other will help you make the right adjustments so i'll give you a quick breakdown. the LSN and MRN work with each other adjusting the fuel consumption from idle to the mid rpm range, these needles should be adjusted together to achieve the optimum tune. for example if you lean the lsn 1 hour you should richen the mrn 1 hour, and vis-versa. this adjusts the fuel up or down the rpm range w/o changing the overall mixture & consumption, which will effect your idle, as well as low - mid range power. much like adjusting your idle for compensation when playing with LSN these needles effect each other. I hope this helps you have a better understanding of your idling issue.

These engines are extremely easy to tune and soo many ppl don't ever get the lsn, mrn, idle right. they easily tune the top in, lean the bottom a little and call it a day. I'll tell you what tho, if you spend the time and get the bottom dialed in you'll see the full potential of your engine and i bet you're amazed with how awesome they really are. <this goes for any brand or model.

This is why I love Rc tech!! Thank you for all the replies. I will work on it today and let you know what happens.

Check and replace your exhaust gaskets and springs as well.

If hes already cooked gadkets or somthin similar this soon then this motor shouldnt even run. He barely had 2 quarts threw it. His carb could have been put on to tight causing a tear in the seal on the inner gasket but if its been sealed then i wouldnt day that can cause to much of an issue.